/Engine/Plugins/FX/Niagara/Source/NiagaraEditor/Public/NiagaraNodeAssignment.h
Go through all the external dependencies of this node in isolation and add them to the reference id list.
virtual void GatherExternalDependencyData ( [ENiagaraScriptUsage](API\Plugins\Niagara\ENiagaraScriptUsage) InUsage, const [FGuid](API\Runtime\Core\Misc\FGuid) & InUsageId, [TArray](API\Runtime\Core\Containers\TArray)< [FNiagaraCompileHash](API\Plugins\NiagaraCore\FNiagaraCompileHash) > & InReferencedCompileHashes, [TArray](API\Runtime\Core\Containers\TArray)< [FString](API\Runtime\Core\Containers\FString) > & InReferencedObjs ) const